session/
lib.rs

1// Copyright 2023 Greptime Team
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15pub mod context;
16pub mod hints;
17pub mod protocol_ctx;
18pub mod query_id;
19pub mod query_options;
20pub mod session_config;
21pub mod table_name;
22pub mod write_progress;
23
24use std::collections::{HashMap, VecDeque};
25use std::net::SocketAddr;
26use std::sync::{Arc, RwLock};
27use std::time::Duration;
28
29use auth::UserInfoRef;
30use common_catalog::build_db_string;
31use common_catalog::consts::{DEFAULT_CATALOG_NAME, DEFAULT_SCHEMA_NAME};
32use common_recordbatch::cursor::RecordBatchStreamCursor;
33pub use common_session::ReadPreference;
34use common_time::Timezone;
35use common_time::timezone::get_timezone;
36use context::{ConfigurationVariables, QueryContextBuilder};
37use derive_more::Debug;
38
39use crate::context::{Channel, ConnInfo, QueryContextRef, dialect_for_channel};
40
41/// Maximum number of warnings to store per session (similar to MySQL's max_error_count)
42const MAX_WARNINGS: usize = 64;
43
44/// Session for persistent connection such as MySQL, PostgreSQL etc.
45#[derive(Debug)]
46pub struct Session {
47    catalog: RwLock<String>,
48    mutable_inner: Arc<RwLock<MutableInner>>,
49    conn_info: ConnInfo,
50    configuration_variables: Arc<ConfigurationVariables>,
51    // the process id to use when killing the query
52    process_id: u32,
53}
54
55pub type SessionRef = Arc<Session>;
56
57/// A container for mutable items in query context
58#[derive(Debug, Clone)]
59pub(crate) struct MutableInner {
60    schema: String,
61    user_info: UserInfoRef,
62    timezone: Timezone,
63    query_timeout: Option<Duration>,
64    read_preference: ReadPreference,
65    /// Latest procedure ID recorded during statement execution, before
66    /// `post_execute` hooks and protocol transmission.
67    last_procedure_id: Option<String>,
68    /// Request-level WAL policy for ordinary inserts.
69    skip_wal: bool,
70    #[debug(skip)]
71    pub(crate) cursors: HashMap<String, Arc<RecordBatchStreamCursor>>,
72    /// Warning messages for MySQL SHOW WARNINGS support
73    warnings: VecDeque<String>,
74}
75
76impl Default for MutableInner {
77    fn default() -> Self {
78        Self {
79            schema: DEFAULT_SCHEMA_NAME.into(),
80            user_info: auth::userinfo_by_name(None),
81            timezone: get_timezone(None).clone(),
82            query_timeout: None,
83            read_preference: ReadPreference::Leader,
84            last_procedure_id: None,
85            skip_wal: false,
86            cursors: HashMap::with_capacity(0),
87            warnings: VecDeque::new(),
88        }
89    }
90}
91
92impl Session {
93    pub fn new(
94        addr: Option<SocketAddr>,
95        channel: Channel,
96        configuration_variables: ConfigurationVariables,
97        process_id: u32,
98    ) -> Self {
99        Session {
100            catalog: RwLock::new(DEFAULT_CATALOG_NAME.into()),
101            conn_info: ConnInfo::new(addr, channel),
102            configuration_variables: Arc::new(configuration_variables),
103            mutable_inner: Arc::new(RwLock::new(MutableInner::default())),
104            process_id,
105        }
106    }
107
108    pub fn new_query_context(&self) -> QueryContextRef {
109        QueryContextBuilder::default()
110            // catalog is not allowed for update in query context so we use
111            // string here
112            .current_catalog(self.catalog.read().unwrap().clone())
113            .mutable_session_data(self.mutable_inner.clone())
114            .sql_dialect(dialect_for_channel(self.conn_info.channel))
115            .configuration_parameter(self.configuration_variables.clone())
116            .channel(self.conn_info.channel)
117            .process_id(self.process_id)
118            .conn_info(self.conn_info.clone())
119            .build()
120            .into()
121    }
122
123    /// Cursors are shared across query contexts created from this session.
124    pub fn get_cursor(&self, name: &str) -> Option<Arc<RecordBatchStreamCursor>> {
125        let guard = self.mutable_inner.read().unwrap();
126        guard.cursors.get(name).cloned()
127    }
128
129    pub fn conn_info(&self) -> &ConnInfo {
130        &self.conn_info
131    }
132
133    pub fn timezone(&self) -> Timezone {
134        self.mutable_inner.read().unwrap().timezone.clone()
135    }
136
137    pub fn read_preference(&self) -> ReadPreference {
138        self.mutable_inner.read().unwrap().read_preference
139    }
140
141    pub fn set_timezone(&self, tz: Timezone) {
142        let mut inner = self.mutable_inner.write().unwrap();
143        inner.timezone = tz;
144    }
145
146    pub fn set_read_preference(&self, read_preference: ReadPreference) {
147        self.mutable_inner.write().unwrap().read_preference = read_preference;
148    }
149
150    pub fn user_info(&self) -> UserInfoRef {
151        self.mutable_inner.read().unwrap().user_info.clone()
152    }
153
154    pub fn set_user_info(&self, user_info: UserInfoRef) {
155        self.mutable_inner.write().unwrap().user_info = user_info;
156    }
157
158    pub fn set_catalog(&self, catalog: String) {
159        *self.catalog.write().unwrap() = catalog;
160    }
161
162    pub fn catalog(&self) -> String {
163        self.catalog.read().unwrap().clone()
164    }
165
166    pub fn schema(&self) -> String {
167        self.mutable_inner.read().unwrap().schema.clone()
168    }
169
170    pub fn set_schema(&self, schema: String) {
171        self.mutable_inner.write().unwrap().schema = schema;
172    }
173
174    pub fn get_db_string(&self) -> String {
175        build_db_string(&self.catalog(), &self.schema())
176    }
177
178    pub fn process_id(&self) -> u32 {
179        self.process_id
180    }
181
182    pub fn warnings_count(&self) -> usize {
183        self.mutable_inner.read().unwrap().warnings.len()
184    }
185
186    pub fn warnings(&self) -> Vec<String> {
187        self.mutable_inner
188            .read()
189            .unwrap()
190            .warnings
191            .iter()
192            .cloned()
193            .collect()
194    }
195
196    /// Add a warning message. If the limit is reached, discard the oldest warning.
197    pub fn add_warning(&self, warning: String) {
198        let mut inner = self.mutable_inner.write().unwrap();
199        if inner.warnings.len() >= MAX_WARNINGS {
200            inner.warnings.pop_front();
201        }
202        inner.warnings.push_back(warning);
203    }
204
205    pub fn clear_warnings(&self) {
206        let mut inner = self.mutable_inner.write().unwrap();
207        if inner.warnings.is_empty() {
208            return;
209        }
210        inner.warnings.clear();
211    }
212}
session/lib.rs

session/
lib.rs
